Kea holding a half a peg

Bruce the beakless kea uses tools to spruce himself up

In a world-first, researchers from the University of Auckland in New Zealand have observed a disabled kea use tools for self-care.

Bruce the kea is missing the top half of his beak from a suspected pest trap accident, but he has learned to carefully select and use pebbles to help preen his feathers.

We’ve known for a while that kea – Nestor notabilis, a large alpine parrot species native to New Zealand – are clever and crafty, able to solve puzzles, make snowballs, raid wheelie bins, and use tools to pry open boxes.

Photographs of Bruce handling objects larger than his preening pebbles, namely: (a) a slice of carrot, (b) a stone, (c) a piece of bark, (d) a black token used in previous cognitive experiments he was a part of. Credit: Bastos et al 2021.

But Bruce is a whole other kettle of bird.

“Kea do not regularly display tool use in the wild, so to have an individual innovate tool use in response to his disability shows great flexibility in their intelligence,” says PhD candidate Amalia Bastos from the University of Auckland.

“They’re able to adapt and flexibly solve new problems as they emerge.”

Bastos is co-author of the paper describing Bruce’s behaviour, published in Scientific Reports. (She’s also previously shown that kea can make complex mathematical judgements about probability.)

After being found by a researcher in 2013 with half his beak missing, Bruce was nursed back to health and now lives in an aviary with many other kea at Willowbank Wildlife Reserve in Christchurch.

He has adapted to his injury, learning to hold large items – like sticks, pebbles and pegs – by hooking them under his tongue and pressing them against his lower beak.

But Bruce’s use of small pebbles for preening is his most impressive adaptation. Although self-care tools have been reported by pet parrots, they’ve rarely been seen in the wild and never before in kea.

Credit: Bastos et al 2021.

But how did the researchers know that Bruce’s tool use was intentional?

Over the course of nine days of observations, Bastos and team worked out five different lines of evidence showing that Bruce meant to use the tool for self-care.

Firstly, 90% of the time he picked up a pebble, he used it to help preen. Secondly, 95% of the times he dropped the pebble, he picked it up again before returning to preening. Thirdly, he selected pebbles of specific sizes suitable for preening.

“The pebbles he picked up were different to those picked up by other kea – they were always of a certain size,” Bastos explains.

Fourth, no other kea in the aviary used pebbles while preening, and fifth, when other kea interacted with objects, they usually picked much larger ones.

“This paper also provides a new framework through which we can provide robust evidence for rare behaviours,” Bastos concludes.

Plus, it’s super cute.